The depressing mood wasn't improved when a weakened Tampines Rovers -- missing injured wingers Jordan Webb and Ryutaro Megumi in addition to departed 2017 stars -- were knocked out of AFC Champions League qualifying at the first hurdle by Bali United on Tuesday night.

The S.League's priority now isn't to stop the exodus -- it can't -- but to mind the gap. The next generation of lion cubs must make their S.League breakthrough as soon as possible and turn the lights back on again.

Michel Sablon worked wonders for Belgium, but can he produce much-needed young stars for Singapore?

Two years later and here we are. Just about every egg has been thrown into Sablon's basket. The kids need to be all right because the S.League almost certainly won't be if its nascent stars fail to shine.

The previous constellation has crossed the Causeway.

Once the age restrictions were announced -- the Young Lions must all be under-22 and the other six local clubs must have six under-23s in their squads -- the S.League's elder statesmen were always going to have their heads turned.

But the speed and size of the exodus is a cause for alarm. For the first time, the number of Singaporeans playing overseas will reach double figures -- and the S.League season is still more than two months away.

Agents are still working the phones. Players are restless. Others will follow. The list is already long, certainly longer than most observers predicted when the FAS' raft of changes were revealed before Christmas.

Even Precious Emuejeraye, a naturalised Singaporean, turns out for Churchill Brothers in India's I-League, which is hardly a ringing endorsement for the maligned Foreign Talent Scheme.

Taken at face value, an overseas stint potentially benefits both the footballer and the national side.

The Brazilians send more footballers abroad than any other nation (more than 1,200). They have also won more World Cups than any other nation (five).

Intriguingly, the French came second with 781 expatriate footballers, according to a CIES Football Observatory study, and Argentina are third (753). Both countries are also World Cup winners.

But the quality of the foreign leagues is perhaps more important than the quantity of expatriate players. When it comes to the Brazilian expats, for instance, 65 percent are based in the higher echelons of European football, a pertinent point that Sablon has made before.

The Belgian coach helped to shape his country's current golden generation, grooming the likes of Eden Hazard for careers with superior foreign clubs. He understands more than most the intrinsic value of an overseas move.

But the move should be a significant upgrade, rather than a sideways shift for short-term financial or bureaucratic reasons.

Two years ago, Sablon underlined the importance of Singaporeans joining a foreign club, but only if the personal and professional benefits were self-evident.

It's a subtle difference, but one that has got a little lost in the debate. Fandi Ahmad, to use the most obvious example, joined Groningen to play with much better players in a foreign culture and climate. They were pull factors.

Today's Lions are moving to Malaysia and Thailand to play with footballers of a similar quality in a familiar culture and climate, largely because Singapore is proving itself to be no country for old men. That's a push factor.

Good luck to those Lions who've headed north of course. Many of them are in their late 20s and early 30s. The S.League's new age quotas are as lopsided as they are arbitrary and careers are short. Rice bowls need to be protected. But, as Lions coach V. Sundramoorthy travels more often than Phileas Fogg in the coming months to watch his scattered Lions, he might ponder the irony of each incongruous setting.

The stadium names may be different, but the standard of football will be largely the same. And there's nothing much he can do about it.

In some respects, the pressure has shifted away from Sundram and towards Sablon and his football incubators.

Clearly, the Belgian didn't pluck the year 2018 from the air when he promised a new generation of fledgling footballers. Similarly, it cannot be a coincidence that the FAS imposed a number of age restrictions in the same year.

The upcoming season must be springtime for the S.League. Like the cherry blossom festival in Japan, FAS coaches are presumably gathering around green spaces and waiting for their saplings to bloom.

It is a noble gamble, one that requires tolerance and understanding, qualities not typically found on the S.League's sweaty, concrete terraces.

Lions are leaving. Fewer foreigners are coming in and household names are dwindling. Patience is not likely to be a virtue among supporters next season. The void needs to be filled quickly.

Like Simon Cowell scouting a new boy band, Sablon must produce talented teenagers with the X factor to sustain interest in the S.League.

Singapore-based Neil Humphreys is an award-winning British author and football writer whose latest book, Rich Kill Poor Kill, is out now.